Early glycemic control, age at onset, and development of microvascular complications in childhood-onset type 1 diabetes: a population-based study in northern Sweden

Good glycemic control remains crucial in prevention of late diabetic complications--the Linköping Diabetes Complications Study

BACKGROUND

Several intervention studies have convincingly demonstrated the importance of good glycemic control to avoid long-term diabetic complications, but the importance of other risk factors remains controversial. We previously reported a markedly reduced incidence of severe retinopathy and nephropathy during the past decades in an unselected population of type 1 diabetes mellitus diagnosed in childhood. The aim of the present study was to analyze possible risk factors, which could explain the improved prognosis.

METHODS

In this longitudinal population-based cohort study, we followed all 269 patients in whom type 1 diabetes mellitus was diagnosed in childhood 1961-1985 in a well-defined geographical area in Sweden. The patients were followed until the end of 1990 s. Multivariable regression models were used to analyze the importance of hemoglobin A1c (HbA(1c)), diabetes duration, blood pressure, cardiovascular risk factors and persisting C-peptide secretion for the development of diabetic retinopathy and nephropathy.

RESULTS

Beside longer duration and higher HbA(1c), blood pressure and lipid values were higher and cardiovascular disease and smoking were more common in patients with severe complications. However, multivariable analysis abolished these associations. Diabetes duration and long-term HbA(1c) were the only significant independent risk factors for both retinopathy and nephropathy. The risk of overt nephropathy increased substantially when HbA(1c) was above 9.6% [Diabetes Control and Complications Trial (DCCT) corrected value], while the risk of severe retinopathy increased already when HbA(1c) exceeded 8.6%.

CONCLUSION

In this unselected population, glycemic control was the only significant risk factor for the development of long-term complications.

Diabetes in Hispanic American youth: prevalence, incidence, demographics, and clinical characteristics: the SEARCH for Diabetes in Youth Study

OBJECTIVE

To report the 2001 prevalence and 2002-2005 incidence of type 1 and type 2 diabetes in Hispanic American youth and to describe the demographic, clinical, and behavioral characteristics of these youth.

RESEARCH DESIGN AND METHODS

Data from the SEARCH for Diabetes in Youth Study, a population-based multicenter observational study of youth aged 0-19 years with physician-diagnosed diabetes, were used to estimate the prevalence and incidence of type 1 and type 2 diabetes. Information obtained by questionnaire, physical examination, and blood and urine collection was analyzed to describe the characteristics of youth who completed a study visit.

RESULTS

Among Hispanic American youth, type 1 diabetes was more prevalent than type 2 diabetes, including in youth aged 10-19 years. There were no significant sex differences in type 1 or type 2 diabetes prevalence. The incidence of type 2 diabetes for female subjects aged 10-14 years was twice that of male subjects (P < 0.005), while among youth aged 15-19 years the incidence of type 2 diabetes exceeded that of type 1 diabetes for female subjects (P < 0.05) but not for male subjects. Poor glycemic control, defined as A1C >or=9.5%, as well as high LDL cholesterol and triglycerides were common among youth aged >or=15 years with either type of diabetes. Forty-four percent of youth with type 1 diabetes were overweight or obese.

CONCLUSIONS

Factors such as poor glycemic control, elevated lipids, and a high prevalence of overweight and obesity may put Hispanic youth with type 1 and type 2 diabetes at risk for future diabetes-related complications.

The body projects of university students with type 1 diabetes

Young adults with type 1 diabetes are a "forgotten group." Their perspectives are rarely addressed by research studies, meaning that we know little about the reasons why they engage (or not) in diabetes self-care practices. The limited work that has investigated these young people's perspectives suggests that they experience a tension between being healthy and being normal. In this article, I examine this tension from the viewpoints of a particular group of young adults with diabetes: university students. I examine what being normal means for these students and how their attempts to be normal impact upon their diabetes control. I argue that normalcy for these students is constructed and maintained through the body. Respondents attempt to be normal by engaging in what Shilling refers to as "body projects." Each of the body projects that students are involved in developing is intended to produce a particular kind of normal embodied identity that is unaffected by diabetes. Unfortunately, the constitutional practices of particular body projects often undermine those of others, and can be risky for students' diabetes control. As such, students have to reach a balance between their different body projects. This article helps to address the lack of research on the perspectives of young adults with diabetes, and contributes to theoretical research on the concept of body projects.

Improved glycemic control and lower frequency of severe hypoglycemia with insulin detemir; long-term experience in 105 children and adolescents with type 1 diabetes

OBJECTIVE

To assess the effect of the insulin analog detemir on glycemic control and severe hypoglycemia in children and adolescents with type 1 diabetes.

RESEARCH DESIGN AND METHODS

A retrospective chart analysis was performed in 105 patients with type 1 diabetes after switching to insulin detemir between 2004 and 2007. In children below 12 yr of age (n = 53), evening neutral protomin hagedorn (NPH) insulin was replaced by insulin detemir if therapeutic goals were not reached and blood glucose levels were unpredictable or hardly controllable. In adolescents above 12 yr of age (n = 52), insulin detemir was started when changing to intensified insulin therapy.

RESULTS

In children below 12 yr of age, hemoglobin A1c (HbA1c) at start was 8.3 +/- 0.8% and after 12 months of treatment with insulin detemir significantly lowered (7.6 +/- 0.6%, p < 0.001). In the age-group above 12 yr of age at the start of the study, the improvement of HbA1c after 12 months of treatment was less pronounced (8.0 +/- 1.2 vs. 7.6 +/- 1.0%) but still significant (p < 0.01). The risk for severe hypoglycemia was significantly decreased compared with patients attending the outpatient clinic between 1995 and 2003 (4.8/100 patient years vs. 7.6/100 patient years, p = 0.003). From the beginning to the end of the follow-up period, body mass index dropped significantly in children below 12 yr of age but no effect was observed in adolescents.

CONCLUSIONS

Use of insulin detemir allows a safe nocturnal glycemic control in children and adolescents with type 1 diabetes and is associated with significantly improved HbA1c levels and fewer severe hypoglycemic events. This makes insulin detemir a most valuable new tool for the treatment of children and adolescents with type 1 diabetes.

Age at diagnosis, gender, and metabolic control in children with type 1 diabetes

OBJECTIVE

To examine whether age at diagnosis and gender affect early metabolic control in children with type 1 diabetes.

DESIGN AND METHODS

Data on age at diagnosis, gender, pubertal status, and metabolic control were gathered by a retrospective chart review of children diagnosed between 1992 and 2005. Mean hemoglobin A1c (HbA1c) values were compared at five time points: at diagnosis and at 6, 12, 24, and 36 months after diagnosis.

RESULTS

At diagnosis, girls aged 6-12 years presented with significantly higher HbA1c levels than girls diagnosed at older or younger ages. Their HbA1c at diagnosis was also significantly higher than that in boys of the same age. There was no gender difference among children diagnosed at ages 0-5 or 13+ yr. At 6 months after diagnosis, only age at diagnosis was associated with metabolic control, with children diagnosed when older presenting with lower HbA1c levels. At 12, 24, and 36 months after diagnosis, there were no significant effects of age at diagnosis or gender on glycemic status.

CONCLUSION

At initial diagnosis, girls in the 6-12 age group presented with higher HbA1c levels compared with boys and girls of other age groups. Although endocrine changes associated with puberty may partly explain the findings, more investigation to elucidate mechanisms accounting for the interaction of age and gender with glycemic status is needed.

[Insulin therapy for type 1 diabetes mellitus: past and present]

The discovery of insulin can be considered the milestone of diabetes mellitus history and a great achievement for its treatment. The first insulin available was the regular. Afterwards, Hagedorn added the protamine to the insulin, thus, creating the NPH insulin. In the 1950s an insulin free of protamine was synthesized: the lente insulin. With the advent of molecular biology, synthetic human insulin was synthesized using recombinant DNA technology. Most recently several types of insulin analogues were available, providing the patients with better metabolic control. Type 1 diabetes mellitus treatment includes plain substitution and individualization for short-acting plus long-acting insulin according to the physician's assistance, besides regular practice of physical activities and diet orientations. In type 1 diabetes mellitus the insulin of low variability is the best choice since basal/bolus insulin therapy or continuous subcutaneous insulin infusion pump can mimetize the physiological release of insulin by beta cells.

Diabetic nephropathy in children and adolescents

Type 1 diabetes mellitus (T1DM) commonly occurs in childhood or adolescence, although the rising prevalence of type 2 diabetes mellitus (T2DM) in these age groups is now being seen worldwide. Diabetic nephropathy (DN) develops in 15-20% of subjects with T1DM and in similar or higher percentage of T2DM patients, causing increased morbidity and premature mortality. Although overt DN or kidney failure caused by either type of diabetes are very uncommon during childhood or adolescence, diabetic kidney disease in susceptible patients almost certainly begins soon after disease onset and may accelerate during adolescence, leading to microalbuminuria or incipient DN. Therefore, all diabetics warrant ongoing assessment of kidney function and screening for the earliest manifestations of renal injury. Pediatric health care professionals ought to understand about risk factors, strategy for prevention, method for screening, and treatment of early DN. This review considers each form of diabetes separately, including natural history, risk factors for development, screening for early manifestations, and strategy recommended for prevention and treatment of DN in children and adolescents.

Intensive insulin therapy in preschool-aged diabetic children: from multiple daily injections to continuous subcutaneous insulin infusion through indwelling catheters

In this study, glycemic control, diabetes care indices and quality of life (QoL) were assessed in 2 groups of newly diagnosed Type 1 diabetic subjects <6 yr old who were randomized to multiple daily injections with (Group A) or without (Group B) an indwelling catheter. Group A [12 males (M)/8 females (F), mean age 3.2+/-1.4 yr] and Group B (9M/11F, mean age 3.9+/-1.8 yr) were evaluated at baseline and after 6 and 12 months of treatment. No significant difference was observed in metabolic control (glycosylated hemoglobin) or in the number of hypoglycemic events between the groups. Patients in Group A had a greater number of daily insulin injections, monitored blood glucose more frequently and had a lower total daily insulin dose per kg (p<0.05). QoL was better in group A. At the end of the study 30% of group A patients progressed to continuous sc insulin infusion (CSII), while no child in Group B switched to a different insulin regimen. Based on these findings, indwelling catheter therapy may be helpful for selected CSII candidates.

Diabetic nephropathy in 27,805 children, adolescents, and adults with type 1 diabetes: effect of diabetes duration, A1C, hypertension, dyslipidemia, diabetes onset, and sex

OBJECTIVE

To give an up-to-date profile of nephropathy and the involvement of risk factors in a large, prospective cohort of patients with type 1 diabetes and largely pediatric and adolescent onset of disease.

RESEARCH DESIGN AND METHODS

A total of 27,805 patients from the nationwide, prospective German Diabetes Documentation System survey were included in the present analysis. Inclusion criteria were at least two documented urine analyses with identical classification. Urine analyses, treatment regimens, diabetes complications, and risk factors were recorded prospectively. Baseline characteristics were age at diagnosis 9.94 years (median [interquartile range 5.8-14.3]), age at last visit 16.34 years (12.5-22.2), and follow-up time 2.5 years (0.43-5.3). Cumulative incidence of nephropathy was tested by Kaplan-Meier analysis and association with risk factors by logistic regression.

RESULTS

Nephropathy was classified as normal in 26,605, microalbuminuric in 919, macroalbuminuric in 78, and end-stage renal disease (ESRD) in 203 patients. After calculated diabetes duration of 40 years, 25.4% (95% CI 22.3-28.3) had microalbuminuria and 9.4% (8.3-11.4) had macroalbuminuria or ESRD. Risk factors for microalbuminuria were diabetes duration (odds ratio 1.033, P < 0.0001), A1C (1.13, P < 0.0001), LDL cholesterol (1.003, P < 0.0074), and blood pressure (1.008, P < 0.0074), while childhood diabetes onset (1.011, P < 0.0001) was protective. Male sex was associated with the development of macroalbuminuria.

CONCLUSIONS

Diabetes duration, A1C, dyslipidemia, blood pressure, and male sex were identified as risk factors for nephropathy. Therefore, besides the best possible metabolic control, early diagnosis and prompt treatment of dyslipidemia and hypertension is mandatory in patients with type 1 diabetes.

Continuous subcutaneous insulin infusion attenuated glycemic instability in preschool children with type 1 diabetes mellitus

BACKGROUND/AIMS

Continuous subcutaneous insulin infusion (CSII) is believed to decrease glycemic instability and hypoglycemia while increasing quality of life compared to insulin injection regimens. To evaluate indices of glycemic control and impact on quality of life, we studied a group of preschool children with type 1 diabetes mellitus (DM) on CSII.

METHODS

Fourteen patients (eight girls and six boys) 3.9 +/- 0.8 years old with DM duration of 2.0 +/- 0.8 years were transitioned from flexible multiple daily insulin (FMDI) (pre-meal aspart and bedtime glargine) to CSII. Patients were evaluated with hemoglobin A(1c) (HbA(1c)) and continuous glucose monitoring quarterly for 1 year. Mean blood glucose (MBG), mean amplitude of glycemic excursion (MAGE), and hypoglycemic events (blood glucose <60 mg/dL) were determined. Patients' parents completed quality of life [TNO-AZL Preschool Children Quality of Life (TAPQoL)] questionnaires for their children at baseline and 1.0 year.

RESULTS

The total daily insulin and the bolus:basal ratio did not change during CSII (0.72 +/- 0.21 vs. 0.74 +/- 0.16 U/kg/day and 2.1 +/- 0.61 vs. 2.40 +/- 0.58 U/kg/day, respectively). There was no change in HbA(1c) (8.0 +/- 0.50% vs. 7.8 +/- 0.40%) or frequency of hypoglycemia (moderate, 92.3 vs. 73.1 events/100 patient-years; severe, 22.5 vs. 17.5 events/100 patient-years). The MBG (213 +/- 94 vs. 185 +/- 79 mg/dL) and frequency (1.9 +/- 1.6 vs. 2.1 +/- 2.2) and duration (nocturnal, 135 +/- 141 vs. 120 +/- 103 min; total, 267 +/- 222 vs. 189 +/- 148 min) of hypoglycemic events did not decrease, whereas MAGE was reduced on CSII (210 +/- 31 vs. 168 +/- 22 mg/dL, P < 0.005). The quality of life subscales on the TAPQoL questionnaire did not change on CSII.

CONCLUSIONS

CSII improved glycemic instability without reducing HbA(1c) or frequency and duration of hypoglycemic events and altering the parent's perception of his or her child's quality of life. CSII improves glycemic instability and is an effective alternative to FMDI therapy in young children with type 1 DM.

School performance in children with type 1 diabetes--a population-based register study

AIMS/HYPOTHESIS

We examined the school marks of diabetic children in Sweden at the time of leaving compulsory education. Marks were examined in comparison with non-diabetic children and with special regard to age at onset of diabetes.

SUBJECTS AND METHODS

The study involved 5,159 children who developed diabetes between 1 July 1977 and 1 July 2000, and 1,330,968 non-diabetic children. We linked the nationwide Swedish Childhood Diabetes Register to the Swedish School-Mark Register, which contains school marks for all children in Sweden at the time of leaving compulsory education (usually at 16 years old). Adjustment was made for potential confounders such as year of birth, maternal age, parity and educational level.

RESULTS

The mean of all numerical school marks for diabetic children was slightly but statistically significantly lower than those of the referent children (3.15 +/- 0.01 [mean + SD] vs 3.23, p < 0.001). The lowest mean score was among children with diabetes diagnosis before the age of 2 years (2.97 +/- 0.09 vs 3.08-3.17 in the older age groups, p = 0.10). When individual subjects were studied (sports, mathematics, English and Swedish), a more complex picture emerged. In four subjects (mathematics, English, Swedish and sports) the risk of a diabetic child not getting a school mark or not passing was increased; in sports and English the diabetic children had significantly reduced odds of getting a high mark.

CONCLUSIONS/INTERPRETATION

Despite a well-developed diabetes care system, we have not succeeded in preventing the disease from affecting school achievements. Among children with a young age at onset and therefore longer duration, the negative effects tend to be greater.

Glycaemic control and hypoglycaemia in children, adolescents and young adults with unstable type 1 diabetes mellitus treated with insulin glargine or intermediate-acting insulin

In this open study of clinical practice, 142 paediatric patients with type 1 diabetes mellitus (>1 year duration), stratified by age, received prandial insulin (regular or lispro) and either once daily insulin glargine (GLAR; n=74), titrated to target fasting blood glucose (FBG) levels 4.4-7.8 mmol/l, or NPH/semilente insulin (NPH insulin, administered once, twice or three times daily; n=68), titrated to target FBG 4.4-8.9 mmol/l. Both groups were treated for 20 +/- 10 months. HbA(1c) significantly increased in GLAR (7.3 +/- 1.0% to 7.6 +/- 1.1%; p = 0.003) and NPH/semilente insulin (7.7 +/- 1.6% to 8.3 +/- 1.5%; p = 0.0001) treated patients. The incidence of symptomatic hypoglycaemia was comparable between GLAR versus NPH/semilente insulin at endpoint (2.19 vs. 1.94 episodes/week); however, the overall incidence of severe hypoglycaemia was significantly lower with GLAR versus NPH/semilente insulin (0.14 vs. 0.73 events/patient-year; p = 0.002). The daily insulin dose was similar between the treatment groups; however, perceived quality of life (QoL) was better with GLAR. GLAR is associated with equivalent glycaemic control, less severe hypoglycaemia and improved QoL compared with NPH/semilente insulin.

Diabetes mellitus en niños y adolescentes: complicaciones crónicas y enfermedades asociadas

Diabetes is one of the most common chronic diseases. Type 1, or autoimmune, diabetes accounts for more than 95 % of cases in children and adolescents. Chronic hyperglycemia per se is responsible for the development of several microvascular (retinopathy, nephropathy, neuropathy) and macrovascular complications (ischemic heart disease, cerebrovascular disease, and peripheral vascular disease). Other autoimmune diseases are also more frequent in type 1 diabetic patients. The present review aims to provide an update on some recent advances in this field to aid early detection of these complications and prevent or delay their progression through improved metabolic control.

A functional polymorphism in the manganese superoxide dismutase gene and diabetic nephropathy

Oxidative stress has been suggested to contribute to the development of diabetic nephropathy. Manganese superoxide dismutase (MnSOD) protects the cells from oxidative damage by scavenging free radicals. The demand for antioxidants is increased by smoking, which could disturb the balance between antioxidants and radicals. The present study aimed to determine whether a valine/alanine polymorphism in MnSOD (V16A, rs4880), alone or in combination with smoking, can contribute to development of diabetic nephropathy in 1,510 Finnish and Swedish patients with type 1 diabetes. Overt diabetic nephropathy (n = 619) was defined as having an albumin excretion rate (AER) >200 microg/min or renal replacement therapy; incipient diabetic nephropathy was defined as having an AER of 20-200 microg/min (n = 336). The control subjects had diabetes duration of >or=20 years, without albuminuria (AER <20 microg/min) and without antihypertensive treatment (n = 555). In addition to male sex and elevated A1C, smoking was significantly associated with diabetic nephropathy (overt plus incipient), odds ratio (OR) 2.00 (95% CI 1.60-2.50). When controlling for age at onset, diabetes duration, A1C, smoking, and sex, the Val/Val genotype was associated with an increase in risk of diabetic nephropathy (1.32 [1.00-1.74], P = 0.049). When evaluating the combined effect of genotype and smoking, we used logistic regression with stratification according to smoking status and genotype. The high-risk group (ever smoking plus Val/Val genotype) had 2.52 times increased risk of diabetic nephropathy (95% CI 1.73-3.69) compared with the low-risk group, but no departure from additivity was found. Our results indicate that smoking and homozygosity for the MnSOD Val allele is associated with an increased risk of diabetic nephropathy, which supports the hypothesis that oxidative stress contributes to the development of diabetic nephropathy.

Natural history and risk factors for microalbuminuria in adolescents with type 1 diabetes: a longitudinal study

OBJECTIVE

To describe the natural history and risk factors for persistent microalbuminuria in children and adolescents with type 1 diabetes followed for up to 15 years.

RESEARCH DESIGN AND METHODS

This study contained a longitudinal cohort of 972 patients; analysis of baseline risk factors was performed using logistic regression and predictors over time using survival analysis. Albumin excretion rate was measured on three consecutive timed overnight urine collections on at least two occasions. Normoalbuminuria was defined as a median albumin excretion rate < 7.5 microg/min, borderline microalbuminuria as 7.5-20 microg/min, and microalbuminuria as 20-200 microg/min. Microalbuminuria was further classified as persistent if its duration was >12 months. Median age was 12.7 years (interquartile range 11.5-14.4) and diabetes duration 6.5 years (4.1-9.3) at first assessment, and median follow-up was 6.2 years (range 1-15.3).

RESULTS

The incidence of persistent microalbuminuria was 4.6 (95% CI 3.3-6.1) per 1,000 patient-years. Predictors of persistent microalbuminuria from the first assessment using multiple logistic regression were high cholesterol (odds ratio 2.2 [95% CI 1.2-4.0]) and borderline microalbuminuria (2.5 [1.2-5.2]). Predictors using Cox regression were HbA(1c) (hazard ratio 1.4 [95% CI 1.1-1.7]), age at diagnosis (1.2 [1.1-1.3]), obesity (3.6 [0.8-15.5]), and insulin dose (2.7 [1.0-7.5]).

CONCLUSIONS

Children and adolescents with type 1 diabetes who have borderline microalbuminuria are more than twice as likely to develop persistent microalbuminuria. In addition to poor glycemic control, clinical markers of insulin resistance were associated with an increased risk of microalbuminuria.

Feasibility and safety of insulin pump therapy in children aged 2 to 7 years with type 1 diabetes: a retrospective study

BACKGROUND AND OBJECTIVES

Although insulin pump therapy has been successful in adults, adolescents and school children, its use has been limited in young children. The purpose of this study was to evaluate the glycemic control, safety and efficacy of continuous subcutaneous insulin infusion via pump in young children (2-7 years old) with type 1 diabetes who were transitioned from twice-a-day insulin injection (neutral protamine Hagedorn/Lente + Humalog/Novalog) to insulin pump therapy. Hemoglobin A1c, BMI, average fasting blood glucose, episodes of severe hypoglycemia, episodes of diabetic ketoacidosis, episodes of lipohypertrophy, blood glucose variability, and number of sick day calls were compared before and after insulin pump therapy.

METHODS

Data were collected retrospectively by chart review over a 2-year period during quarterly diabetes clinic visits from 33 patients who were managed on neutral protamine Hagedorn/Lente + Humalog/Novolog twice-a-day injections for at least 1 year prior to transitioning to insulin pump therapy.

RESULTS

There was a significant improvement in the average hemoglobin A1c after continuous subcutaneous insulin infusion therapy. The average fasting blood sugar was lower in the continuous subcutaneous insulin infusion group. Severe episodes of hypoglycemia and episodes of lipohypertrophy were significantly higher before insulin pump therapy initiation. There were significantly fewer sick day calls after continuous subcutaneous insulin infusion. Blood sugar variability improved significantly after insulin pump therapy. There was no significant difference in BMI or amount of carbohydrate consumed. None of the patients experienced diabetic ketoacidosis requiring emergency treatment before or after insulin pump therapy.

CONCLUSIONS

Continous subcutaneous insulin infusion therapy in young children with type 1 diabetes is a safe, effective and superior alternative to a twice-a-day insulin regimen.

[Continuous subcutaneous insulin infusion in pediatric patients with type 1 diabetes mellitus]

INTRODUCTION

To determine the efficacy and safety of continuous subcutaneous insulin infusion therapy in a group of children and adolescents with type 1 diabetes mellitus.

PATIENTS AND METHODS

Data from 17 patients were collected during the first year of continuous subcutaneous insulin infusion treatment. All patients were followed-up at our diabetic pediatric clinic. HbA1c, body mass index, insulin dose, severe hypoglycemic episodes, and diabetic ketoacidosis events before and after initiation of pump therapy were compared.

RESULTS

The mean age was 14.02 +/- 3.70 years and the mean diabetes duration was 5.81 +/- 3.31 years. HbA1c decreased from 8.12 +/- 1.46 to 7.52 +/- 0.87 % after 2 months of therapy and this decrease was maintained throughout the first year of continuous subcutaneous insulin infusion treatment. Insulin dose decreased from 0.99 +/- 0.24 to 0.84 +/- 0.18 U/kg/day after 1 year of treatment. Body mass index remained unchanged. There were fewer severe hypoglycemic events after the start of insulin pump therapy (0.47 +/- 1.23 events/patient in the 6 months before continuous insulin infusion, 0.29 +/- 1.20 episodes in the first 6 months of insulin pump therapy and 0.06 +/- 0.24 in the period from 6 to 12 months of the treatment). There were 3 ketoacidosis episodes, all in the same patient.

CONCLUSIONS

Continuous subcutaneous insulin infusion is a safe and effective alternative in the treatment of children and adolescents with type 1 diabetes mellitus. It improves metabolic control and decreases the number of severe hypoglycemic episodes.

Age at onset of childhood-onset type 1 diabetes and the development of end-stage renal disease: a nationwide population-based study

OBJECTIVE

To analyze the impact of age at onset on the development of end-stage renal disease (ESRD) due to diabetic nephropathy in a nationwide population-based cohort with childhood-onset type 1 diabetes.

RESEARCH DESIGN AND METHODS

A record linkage between two nationwide registers, the Swedish Childhood Diabetes Registry, including 12,032 cases with childhood-onset diabetes, and the Swedish Registry for Active Treatment of Uraemia was performed. Log-rank test was used to test differences between cumulative risk curves of developing ESRD due to diabetic nephropathy in three different strata of age at onset (0-4, 5-9, and 10-14 years).

RESULTS

At a maximum follow-up of 27 years, 33 patients had developed ESRD due to diabetic nephropathy and all had a diabetes duration >15 years. In total, 4,414 patients had diabetes duration >15 years, and thus the risk in this cohort to develop ESRD was 33 of 4,414 (0.7%). A significant difference in risk of developing ESRD was found between the youngest (0-4 years) and the two older (5-9 and 10-14 years) age-at-onset strata (P = 0.03 and P = 0.001, respectively). A significant difference in the risk of developing ESRD was also found between children with prepubertal (0-4 and 5-9 years, n = 2,424) and pubertal (10-14 years, n = 2000) onset of diabetes (P = 0.002). No patient with onset of diabetes before 5 years of age had developed ESRD.

CONCLUSIONS

With a median duration of 21 years in this population-based Swedish cohort with childhood-onset diabetes, <1% of the patients had developed ESRD due to diabetic nephropathy, and a prepubertal onset of diabetes seems to prolong the time to development of ESRD.

Early diabetic complications in a population of young patients with type 1 diabetes mellitus despite intensive treatment

AIM

To describe the prevalence of early complications in an unselected population of patients with type 1 diabetes mellitus (DM1) diagnosed in childhood with intensive insulin treatment from diagnosis.

METHODS

Eighty children and adolescents with DM1, age 7-22 years and DM1 duration >3 years, were studied. Neuropathy was defined as abnormal nerve conduction finding in > or = 2 of 4 nerves (sural and peroneal nerves), nephropathy as albumin excretion rate > or = 20 microg/min and retinopathy as all grades of retinal changes in fundus photographs.

RESULTS

The prevalence of neuropathy was 59%, of retinopathy 27% and of nephropathy 5% after 13 years DM1 duration. Mean (SD) long-term HbA1c was 8.4 (0.9)% (DCCT-corrected value).

CONCLUSION

Even in a population with intensive insulin treatment from the beginning and fairly good metabolic control, the prevalence of subclinical neuropathy was high, while other diabetic complications were lower than usually reported.

Glu298Asp and NOS4ab polymorphisms in diabetic nephropathy

BACKGROUND AND AIMS

The risk of diabetic nephropathy (DN) increases with increase in intraglomerular pressure, which may partly be regulated by nitric oxide (NO). NO-production can be affected by polymorphisms in the endothelial NO-synthase gene (NOS3), hyperglycaemia and smoking. We therefore studied association between DN and two polymorphisms in NOS3, Glu298Asp and NOS4ab, in Caucasian type 1 diabetes (T1D) patients.

PATIENTS AND METHODS

A total of 1510 Finnish and Swedish T1D patients were included in a cross-sectional case-control study. Incipient DN was defined as an albumin excretion rate (AER) of 20-200 microg/min (n = 336). Overt DN = AER>200 microg/min or renal replacement therapy (n = 619). All patients with DN were considered as cases. The controls were T1D patients with diabetes duration 20 years, AER<20 microg/min and without antihypertensive treatment (n = 555). The genetic markers studied were a 27 bp repeat (NOS4ab) and Glu298Asp (rs1799983).

RESULTS

Age at onset of diabetes, male sex, duration of diabetes, HbA1c, blood pressure and smoking were assessed as possible confounders in the logistic regression analysis, which showed that homozygosity for the Glu-allele of the Glu298Asp-polymorphism was independently associated with increased risk of DN (OR = 1.46; 95% CI = 1.12-1.91). The variables smoking (OR = 2.13; 95% CI = 1.63-2.78), male sex (OR = 1.61; 95% CI = 1.23-2.10), HbA1c (OR per % increase above upper limit of the normal reference range = 1.02; 95% CI = 1.02-1.03), systolic (OR = 1.05; 95% CI = 1.04-1.06) and diastolic blood pressure (OR = 1.04; 95% CI = 1.02-1.05) also significantly and independently increased the risk of DN when taking age at diabetes onset and diabetes duration into account. The NOS4 a-allele was not associated with DN.

CONCLUSIONS

The Glu/Glu-genotype of the NOS3 Glu298Asp polymorphism may increase the risk of developing DN independently of other known risk factors.

Manganese superoxide dismutase alanine to valine polymorphism and risk of neuropathy and nephropathy in Egyptian type 1 diabetic patients

Oxidative stress, characterized by a marked increase in the level of oxygen free radicals (OFR), has been implicated in the development of diabetic microangiopathic complications, such as diabetic neuropathy (DN) and nephropathy (DP). Antioxidant enzymes may protect against the rapid onset and progression of microangiopathy, by reducing the excess of OFR and peroxides. Mutations and polymorphisms in genes encoding such enzymes may therefore result in a predisposition to this disorder.

AIM

We investigated the role of genes encoding the antioxidant enzyme, mitochondrial superoxide dismutase (Mn-SOD2), in DN and DP pathogenesis in an Egyptian population. We studied Ala(-9)Val polymorphism of the Mn-SOD2 gene in type 1 diabetic patients (n = 65) with DN (n = 40) or DP (n = 45).

METHODS

We used polymerase chain reaction (PCR) assays with restriction fragment length polymorphism for rapid detection of polymorphisms. These assays involved the use of mismatch PCR primers to create restriction sites in the amplified product only in presence of the polymorphic base. The PCR product was then digested with AgeI restriction enzyme to detect Ala(-9)Val polymorphic sites.

RESULTS

The frequencies of the Ala allele (odds ratio (OR) = 0.438, 95% CI of 0.247-0.778) and the Ala/Ala genotype (OR = 0.26, 95% CI of 1.39-10.266) were significantly lower in diabetic neuropathy patients. In contrast, the frequencies of the Val allele (OR = 2.282, 95% CI of 1.286-4.05) and the homozygous Val/Val genotype (OR = 6.68, 95% CI of 0.3-0.76) were significantly higher in patients with DN than diabetics without neuropathy. Although the Val allele was more frequently detected in DP patients than diabetics without nephropathy (OR = 3.2), this difference was statistically non-significant. In conclusion, Ala(-9)Val substitution in the Mn-SOD2 gene was associated with DN in Egyptian diabetic children but not a significant factor in diabetic patients with nephropathy.

Flexible insulin therapy with glargine insulin improved glycemic control and reduced severe hypoglycemia among preschool-aged children with type 1 diabetes mellitus

BACKGROUND AND OBJECTIVES

Insulin replacement regimens now stress the importance of administering throughout the day insulin doses that are based on flexible food choices and focusing on improved metabolic control. A flexible multiple daily insulin (FMDI) regimen (premeal lispro plus bedtime glargine) results in lower hemoglobin A1c (HbA1c) levels and fewer hypoglycemic episodes than does a multiple daily insulin (MDI) regimen among school-aged children and adolescents with type 1 diabetes mellitus (DM). The purpose of this study was to determine the feasibility of FMDI therapy for a group of preschool-aged children with type 1 DM who were transitioned from MDI therapy (premeal lispro plus ultralente insulin twice per day), by comparing BMI, total daily insulin requirements, HbA1c levels, and episodes of severe hypoglycemia.

RESEARCH DESIGN AND METHODS

Data were collected over a 2-year period, during quarterly DM clinic visits, from 35 patients (17 female patients and 18 male patients, 4.8 +/- 1.0 years of age) who had received MDI insulin therapy for > or =1 year before being transitioned to a FMDI regimen.

RESULTS

Although there was no significant change in BMI with FMDI therapy (17.1 +/- 1.8 kg/m2 vs 17.0 +/- 1.7 kg/m2), 43% of patients (6 female subjects and 9 male subjects) were overweight (BMI of >85th percentile for age) both before and after treatment. The total daily insulin requirement (0.67 +/- 0.13 U/kg per day vs 0.78 +/- 0.14 U/kg per day) and bolus/basal insulin ratio (1.1 +/- 0.4 vs 1.9 +/- 0.6) were significantly increased and overall glycemic control was improved after transition to FMDI therapy (HbA1c levels: 8.8 +/- 0.9% vs 8.3 +/- 0.8%). However, HbA1c levels improved only among normal-weight subjects (9.0 +/- 1.0% vs 8.3 +/- 1.0%) and not among overweight subjects (8.7 +/- 0.7% vs 8.4 +/- 0.6%) after FMDI therapy. The overall rate of severe hypoglycemia was significantly decreased with the FMDI regimen (25.5 events per 100 patient-years vs 10.6 events per 100 patient-years) but again only for normal-weight children (29.7 events per 100 patient-years vs 7.4 events per 100 patient-years).

CONCLUSIONS

The use of FMDI therapy with glargine among preschool-aged children with type 1 DM was associated with improved overall glycemic control and decreased frequency of severe hypoglycemia. Although our study did not have a control group, these findings suggest that FMDI regimens may be a feasible therapeutic alternative to MDI treatment for preschool-aged children with type 1 DM. However, excess body weight status appeared to preclude a desirable therapeutic response in this group of patients.

Pediatric aspects of diabetic kidney disease

Type 1 diabetes mellitus (DM1) commonly occurs in childhood, although many pediatric centers are now seeing more cases of type 2 diabetes (DM2). Kidney failure caused by either type of diabetes is uncommon during childhood, but these years of hyperglycemia contribute to long-term complications. All children with diabetes warrant screening of glomerular filtration rate, blood pressure, and urine albumin excretion. Screening should begin after 5 years of DM1 or at puberty. A similar screening strategy should start at the time of diagnosis of DM2. Atypical features such as dipstick positive proteinuria or active urine sediment may warrant referral to a nephrologist for evaluation, including biopsy. The first line of treatment in either form of diabetes is achieving the best glycemic control possible. Patients developing microalbuminuria or hypertension should receive antiangiotensin II drugs. Adult studies suggest blood pressure goals should be lower in diabetes than in the general population. Although direct evidence is not yet available in children, achieving blood pressure below the 90th percentile for age, height, and gender seems prudent. Longitudinal studies and new screening tests may allow detection of susceptible children earlier in the course of DM1 or DM2, perhaps allowing prevention of diabetic kidney disease.